//选项卡
var navLi = document.querySelectorAll('.coffee_top ul li');
var main = document.querySelectorAll('.coffee_bottom ul');
for(var k = 0; k < navLi.length; k++){
	navLi[k].index = k;
	navLi[k].onclick = function(){
		for(var o = 0; o < navLi.length; o++){
			navLi[o].classList.remove('active');
			main[o].classList.remove('active');
		}
		this.classList.add('active');
		main[this.index].classList.add('active');
	}
}
